KMB to test electric bus that recharges itself at each stop

An electric bus that recharges itself at bus stops will go on trial on Hong Kong roads in about two months.

The so-called supercapacitor bus – now being used at the World Expo in Shanghai – is being brought to the city by Kowloon Motor Bus as it seeks ways to reduce emissions from its diesel-burning fleet.

The bus has a quick-charging electricity storage device that can propel it for a kilometre after charging for 30 seconds and five to nine kilometres after a full charge taking three minutes.

One kilometre might seem a short distance, but the bus company’s deputy managing director, Evan Auyang, said this amounted to three to four blocks and as the buses stopped often, the pauses should allow enough time for quick charges.

“Chargers will be installed at our bus stops so that the bus can recharge while loading and offloading passengers, but we won’t need a charger at every stop to begin with,” Auyang said.

The bus will arrive at KMB’s Lai Chi Kok depot in July for the company to test its performance in the city’s hot, humid weather and hilly terrain before deciding whether it can be used to replace some of the older models. When fully charged, the air-conditioned bus can travel for five kilometres with a full load and up to nine kilometres empty.

Its top speed is 55km/h, compared to 70km/h for the diesel buses, so it would only be used on urban routes, where the average speed was 50km/h.

Auyang said the technology would evolve quickly, with US researchers working at doubling power capacity in the same charging time.

The bus would cost more than diesel-fuelled single-deckers, which cost about HK$2 million, but it would be cheaper than hybrids and would cut fuel costs by up to 75 per cent.